Recently I decided to research dog age after running into a woman who described her Golden as old. When I inquired about the dog’s age I learned he was only 8 years old. In comparison I have a 55 pound dog who is 7 years old. I would never describe him as old, not even on his way to being old. But should I?

I knew that contrary to popular belief, one year of a dog’s life is NOT equivalent to seven human years. But what is an accurate comparison between human and dog age? For that answer I reviewed the current thinking of the American Veterinary Medical Association (AVMA) and the American Kennel Club (AKC). Below you’ll see the age charts they use respectively:


 In general, different breeds age differently and small dogs tend to live longer than larger dogs. More specifically, the AVMA offers the following guidelines:

  • 15 human years equals the first year of a medium-sized dog’s life (medium is defined as 21-50 pounds)
  • Year two for a dog equals about nine years for a human
  • And after that, each human year would be approximately five years for a dog

Using this formula the woman’s “old” Golden would be at least 54 (likely older since the dog in question probably weighed in excess of 60 pounds.

My dog, using this formula, would be about 49. He sure doesn’t act like he’s 49!

According to the AKC, small dogs are considered senior at 7 while larger breeds are considered senior when they reach 5 or 6. According to the AVMA, the senior label is assigned because they start seeing more age-related problems in dogs at about 7 for smaller dogs and 5-6 for larger dogs.

Although large mammals like elephants and whales tend to live longer than smaller ones like mice and rabbits, the exact opposite seems to be true for dogs. Why? Researchers aren’t exactly sure but they have found that every 4.4 pounds of body mass reduces a dog’s life expectancy by about a month. Body mass which comes from a larger breed or from being overweight has the same impact. Researchers think this may result from larger breeds being impacted by age related illnesses sooner than smaller breeds. Another possibility is that because larger dogs grow at an accelerated rate they may be more likely to develop abnormal cell growth and death from cancer. More research is underway in an effort to more definitively identify the link between growth and mortality.

Clearly a lot of other factors which are not considered by the AVMA or AKC enter into how long a given dog will live such as:

  • Nutrition over his/her lifetime
  • Good dental care and maintenance
  • Veterinary care received over his/her lifetime
  • Amount of exercise
  • Amount of attention and healthy interaction received
  • Genetic makeup of a given dog – purebred vs. mixed breed, overall health of a dog’s parents, etc.

So back to the Golden that kicked off this investigation in the first place...he is certainly well into middle age at 54+ but I wouldn’t call him “old.” And, regarding my own dog, according to the “experts” he’s definitely middle aged at 49.

Nonetheless, I am still not satisfied with my investigation and here’s why. My last dog was a 75 pound mixed breed. He lived 12 days shy of his 17th birthday. According to the calculators above he would have been well over 100. Why did he live so long? I’d argue that it’s the same reasons my current dog will live for a long time – they both got/get lots of exercise (about 2 hours per day), high quality food and chews, regular veterinary care, lots of love and attention, and both are mixed breeds. So while this isn’t counter to the age calculators, I firmly believe that nutrition, dental care and maintenance, exercise, and quality and quantity of attention and interaction accounts for a much larger portion of life expectancy than any calculator can take into account.

Lastly, attitude probably plays a part. I don't think of my dog as middle aged so I don't expect him to act middle aged - whatever middle aged means. The woman with the Golden sees her 8 year old Golden as "old" so likely interacts with her dog differently than I would if he was my dog.

In general, my advise is to take the "calculators" with a grain of salt. The age tables are interesting but I'm giving my own dog better odds! Time will tell how long he'll live but I expect he'll far exceed what the calculators predict. Fingers crossed anyway.

Note: For those curious, the dog pictured above is my wonder dog, Chuck! His photo was snapped at his sitter's house in September, 2019 - he looks very sad here even though his sitter is great! He's such a sweet boy.